They let Barwin walk , its yet to be seen if Mercilus can fill the void. Huge question mark IMO.

On ST , they let Alan Ball walk , its possible they lose Braman , Carmichael & Dobbins .... those were the four best players on coverage units last season. When you consider how bad those units were , losing the top four has to be a huge concern.

WR I believe is improved as is TE - I believe the Rookie Griffin is a better TE than James Casey , even if not as versatile.

FB has improved by leaps and bounds.

I wonder about the secondary - J.Jo hasn't been himself , but it is preseason.
Can Swearinger fill the role Glover Quin played ?!
How much will Ed Reed contribute?!

Probably the biggest question mark on the entire team is the starting Right Guard .... Will Derrick Newton sideline Matt Schaub for the season ?!

This version of the Texans is definitely considered contenders , before a meaningful game is played but they do have questions that have to be answered favorably ....